Gas tanks made of reinforced plastic or metal have been used in storage facilities of waste gas in iron works, low-pressure fuel gas or the like. Further, at present, attention has been given to biogas processing facilities for recovering methane gas and the like generated from general sewage disposal and pastoral waste disposal facilities, disposal facilities of raw garbage, distilled spirit lees, soy lees or the like, and the like, and utilizing it as energy, and to facilities for making efficient use of gas generated by pyrolysis of organic wastes. In particular, in recent years, according to the needs of the age, new construction of these facilities has increased, and at the same time, an increase in size of the respective facilities has progressed. In these fields, equipment for storing and recovering gas has been expected to be constructed more economically by high-strength and lightweight membrane materials. For example, there is patent document 1 relating to a membrane gas holder. In this document, there is described a box storage type membrane gas holder having a structure that a gas storage bag formed by a bag body made of a flexible membrane material having air tightness and liquid tightness and capable of taking gas in and out is accommodated in a rigid-structure box made of a reinforced plastic material, a metal material or the like. In this document, particularly, no reference is made to a material used in the membrane material for the gas holder, and only a system of the membrane gas holder is described.
On the other hand, as a conventional gas barrier membrane material, there is described in patent document 2 a gas barrier membrane material in which a coating film having transparency obtained by providing an anchor coat layer on at least one surface of a polymer film substrate as needed and forming thereon in turn a thin metal or metal compound membrane layer and a protective layer as needed and a heat-sealable resin are adhered to each other through a gas barrier adhesive containing inorganic ultrafine particles.
Herein, there is a description of the membrane material having excellent gas barrier properties as a highly gas barrier membrane material by filling minute pinhole portions in a thin membrane layer with the ultra finely dispersed inorganic material contained in the barrier adhesive and as a laminated body in which permeation of a large amount of gas from cracks and broken portions of the thin membrane layer which has occurred to expansion and contraction of the film occurring at the time of lamination with another substrate and thermal stress due to heat shock can be inhibited by the adhesive layer. However, use of this invention is a packaging material. Although it is possible to secure gas barrier properties by this membrane material alone, it has been difficult to obtain strength enough to be tolerable in practical use of the membrane material for a gas holder which is use of the present invention.
Further, in patent document 3, there are described an ultra lightweight membrane material having two layers of a base fabric and a gas barrier layer and an ultra lightweight membrane material comprising a resin layer, a base fabric layer and a gas barrier layer.
Use of this invention is a baronet or a diaphragm used in the inside of an airship, and it has been difficult to obtain abrasion resistance and flex resistance enough to be tolerable in practical use.
Patent Document 1: JP-A-2005-48930
Patent Document 2: JP-A-2000-006304
Patent Document 3: JP-A-2005-119232